MacVideo has the option to edit captions that were either automatically generated or through individual upload of SRT files.
Go to My Media and select a media entry with captions.
Select Edit from the Actions drop-down menu.
Select the Captions tab and then click Edit Captions.
You can now see the Caption Editor displayed.
The following options are available:
Change Caption File – If there is more than one caption file for the entry, select a different caption file from the Captions drop-down menu.
To Edit the timestamp of each line – Click on the timestamp in the editor and modify the time. If there is overlapping time, the system highlights the overlapping time.
Search – Enter a search term. The results are highlighted in each caption line.
Search and replace text – Enter the search term, enter the replacement term and click Replace.
Add speaker ID – Select rows and add the speaker ID in the Add Speaker to selected items.
The speaker ID is added in  in the beginning of each line. In this example Ron was added as the speaker for the selected lines.
Auto scroll text – Check Auto scroll to auto scroll the text when playing the media.
When playing the player – the current line is highlighted in the captions file.
Find frame for text – When clicking on a caption line the player jumps to the correct frame for the selected text.
Selecting captions from the existing captions will replace the captions on the page.
Revert changes – reverts to the last saved changes
Save – save the modified caption file.
The Revert & Save button is enabled only when modifying the captions file.
The Replace button is enabled only if the user modifies a value.